The purpose of this study is to determine differences in bone loss between women, in postmenopausal age range and ethnically similar men (ages 55-75 years) and to correlate these differences with blood and urine measurements of bone metabolism. Bone mass decreases with increasing age in both men and women. In addition to differences based on gender and age, there are also differences in bone loss based on race. It has been know for some time that bone loss in black man and women is slower than that in white men and women. Although technology (DEXA scan) aimed at determining bone loss prior to the occurrence of fracture has advanced lately, bone density scans or the measurement of serum indices of bone turnover have not been obtained in aged women. Also, correlation of such with race has not been accomplished. In effect, the absence of this information leaves a substantial portion of the aging population at risk for fracture without the benefit of preventive measures such as hormone replacement in the postmenopausal years, and/or dietary calcium supplementation. We seek to correlate bone mineral density (BMD) at two sites with serum and urine parameters of skeletal turnover over a period of 24 months in a population of aging black and white men and postmenopausal black and white women.